Stannaborates: tuning the ion conductivity of dodecaborate salts with tin substitution

Metal substituted dodecaborate anions can be coupled with alkali metal cations to have great potential as solid-state ion conductors for battery applications. A tin atom can replace a B-H unit within an unsubstituted dodecaborate cage to produce a stable, polar divalent anion. The chemical and structural change in forming a stannaborate results in a modified crystal structure of respective group 1 metal salts, and as a result, improves the material's ion conductivity. Li2B11H11Sn shows high ion conductivity of similar to 8 mS cm-1 at 130 degrees C, similar to the state-of-the-art LiCB11H12 at these temperatures, however, obtaining high ion conductivity at room temperature is not possible with pristine alkali metal stannaborates. The ionic conductivity for lithium, sodium, and potassium stannaborates was been measured along with thermal properties.

Automated summary

Metal substituted dodecaborate anions coupled with alkali metal cations show promise as solid-state ion conductors for batteries. Substituting a B-H unit in an unsubstituted dodecaborate cage with a tin atom produces a stable and polar divalent anion, resulting in improved ion conductivity. Li2B11H11Sn exhibits high ion conductivity at 130 degrees C, similar to LiCB11H12, but achieving high ion conductivity at room temperature is challenging.